What is the recommended treatment for arterial lusoria (aberrant right subclavian artery)?

Management of Aberrant Right Subclavian Artery (Arteria Lusoria)

Primary Treatment Decision

Surgical or endovascular intervention is recommended when the Kommerell's diverticulum orifice exceeds 3.0 cm, the combined diameter of the diverticulum and adjacent descending thoracic aorta exceeds 5.0 cm, or when the patient is symptomatic with dysphagia, respiratory symptoms, or recurrent laryngeal nerve palsy. 1

Initial Diagnostic Workup

All patients discovered to have an aberrant right subclavian artery (ARSA) require dedicated thoracic aortic imaging with CT angiography or MRI, as this anomaly is associated with thoracic aortic aneurysm in 2-8% of cases. 1

Imaging Protocol

• CT angiography is the test of choice for diagnosing ARSA due to its excellent anatomic detail of vascular structures and their relationship to surrounding tissues. 2
• Volume-rendered 3D reconstructions from CTA provide optimal simultaneous analysis of both vascular and bony structures, crucial for evaluating compression of adjacent structures. 2
• MRI/MRA is an excellent alternative when radiation exposure is a concern or when detailed soft tissue evaluation is needed. 2

Critical Measurements

Two key diameter measurements must be obtained using cross-sectional imaging: 1

• The diverticulum orifice (measured radially and longitudinally at the aortic wall)
• The combined diameter of the diverticulum and adjacent descending thoracic aorta (measured from the tip of the diverticulum to the opposite aortic wall)

Indications for Intervention

Absolute Indications

Intervention is warranted in the following scenarios: 3, 1

• Kommerell's diverticulum orifice >3.0 cm
• Combined diameter of diverticulum and adjacent descending aorta >5.0 cm
• Symptomatic patients with dysphagia (dysphagia lusoria), dyspnea, or recurrent laryngeal nerve palsy
• Aneurysmal degeneration with risk of rupture 4
• Arterioesophageal or arteriotracheal fistulae 4

Important Context

Kommerell's diverticulum is present in 20-60% of patients with ARSA, representing a persistent remnant of the fourth primitive dorsal aortic arch. 2, 1 The presence and size of this diverticulum drives the decision for intervention in asymptomatic patients.

Treatment Approach

Symptomatic Patients

For symptomatic patients (dysphagia, dyspnea, compression symptoms), surgical treatment involves: 3, 4, 5

• Resection of the aneurysmal segment of the subclavian artery (the diverticulum) and adjacent aorta
• Replacement of the aorta with a graft
• Revascularization of the right subclavian artery through carotid-subclavian bypass or direct reimplantation to the right common carotid artery

Surgical Options by Patient Population

The surgical approach varies based on patient age and anatomy: 5

• Pediatric patients: Muscle-sparing right thoracotomy provides optimal exposure for mobilization of the distal right subclavian artery and enables direct anastomosis to the ipsilateral carotid artery without graft interposition
• Adult patients: Supraclavicular approach is applicable and reliable, though right anterolateral thoracotomy may be preferred for complex cases 6
• Select patients with noncalcified ARSA origin without aneurysmal degeneration: Robotic-assisted transthoracic resection after right carotid-subclavian bypass represents a viable minimally invasive option 7

Endovascular and Hybrid Approaches

An alternative treatment is exclusion of the right subclavian artery origin and adjacent aorta using an aortic endograft, though long-term follow-up of this endovascular approach is not available and compression may continue. 3

For aneurysmal disease, hybrid techniques combining: 4, 8

• Right subclavian artery transposition or bypass
• Proximal endovascular occlusion or ligation of the lusorian artery
• Endovascular thoracic aortic stent graft implantation for lusorian artery aneurysms

Important caveat: Radio-anatomical studies show that conventional thoracic endovascular aneurysm repair alone is rarely feasible without debranching procedures. A double transposition or bypass (left subclavian artery to left common carotid artery, ARSA to right common carotid artery) is typically necessary to obtain adequate proximal neck (>20 mm) for stent graft implantation. 8

Conservative Management

Asymptomatic patients with ARSA who do not meet size criteria for intervention should be managed conservatively with surveillance imaging to monitor for aneurysmal degeneration or development of symptoms. 1 This is appropriate because ARSA is usually asymptomatic, occurring in approximately 1% of the population. 1

Key Clinical Pitfalls

• Do not confuse ARSA with atherosclerotic subclavian artery stenosis, which has different management algorithms focused on revascularization for subclavian steal syndrome or pre-CABG intervention. 3
• Symptoms typically occur in adults as the artery enlarges, not in childhood, so age at presentation influences surgical approach. 3
• The retroesophageal course (80% of cases) is what causes dysphagia lusoria, distinguishing this from other subclavian pathology. 3
• Long-term outcomes after endovascular exclusion are unknown, and compression symptoms may persist despite endograft placement. 3